cpndatep

Previous coupon date for fixed-income security

Syntax

```PreviousCouponDate = cpndatep(Settle, Maturity, Period, Basis,EndMonthRule, IssueDate, FirstCouponDate, LastCouponDate)
```

Arguments

 `Settle` Settlement date. A vector of serial date numbers or date strings. `Settle` must be earlier than `Maturity`. `Maturity ` Maturity date. A vector of serial date numbers or date strings. `Period` (Optional) Coupons per year of the bond. A vector of integers. Allowed values are 0, 1, 2 (default), 3, 4, 6, and 12. `Basis` (Optional) Day-count basis of the instrument. A vector of integers. 0 = actual/actual (default)1 = 30/360 (SIA)2 = actual/3603 = actual/3654 = 30/360 (PSA)5 = 30/360 (ISDA)6 = 30/360 (European)7 = actual/365 (Japanese)8 = actual/actual (ISMA)9 = actual/360 (ISMA)10 = actual/365 (ISMA)11 = 30/360E (ISMA) 12 = actual/365 (ISDA)13 = BUS/252For more information, see basis. `EndMonthRule` (Optional) End-of-month rule. A vector. This rule applies only when `Maturity` is an end-of-month date for a month having 30 or fewer days. 0 = ignore rule, meaning that a bond's coupon payment date is always the same numerical day of the month. 1 = set rule on (default), meaning that a bond's coupon payment date is always the last actual day of the month. `IssueDate` (Optional) Date when a bond was issued. `FirstCouponDate` (Optional) Date when a bond makes its first coupon payment; used when bond has an irregular first coupon period. When `FirstCouponDate` and `LastCouponDate` are both specified, `FirstCouponDate` takes precedence in determining the coupon payment structure. If you do not specify a `FirstCouponDate`, the cash flow payment dates are determined from other inputs. `LastCouponDate` (Optional) Last coupon date of a bond before the maturity date; used when bond has an irregular last coupon period. In the absence of a specified `FirstCouponDate`, a specified `LastCouponDate` determines the coupon structure of the bond. The coupon structure of a bond is truncated at the `LastCouponDate`, regardless of where it falls, and is followed only by the bond's maturity cash flow date. If you do not specify a `LastCouponDate`, the cash flow payment dates are determined from other inputs.

Required arguments must be number of bonds (`NUMBONDS`)-by-`1` or `1`-by-`NUMBONDS` conforming vectors or scalars. Optional arguments must be either `NUMBONDS`-by-`1` or `1`-by-`NUMBONDS` conforming vectors, scalars, or empty matrices.

Description

```PreviousCouponDate = cpndatep(Settle, Maturity, Period, Basis, EndMonthRule, IssueDate, FirstCouponDate, LastCouponDate)``` returns the previous coupon date on or before settlement for a portfolio of bonds. This function finds the previous coupon date whether or not the coupon structure is synchronized with the maturity date.

For zero coupon bonds the previous coupon date is the issue date, if available. However, if the issue date is not supplied, the previous coupon date for zero coupon bonds is the previous quasi coupon date calculated as if the frequency is semiannual.

`PreviousCouponDate` is returned as a serial date number. The function `datestr` converts a serial date number to a formatted date string.

Examples

```PreviousCouponDate = cpndatep('14 Mar 1997', '30 Jun 2000',... 2, 0, 0); datestr(PreviousCouponDate)```
```ans = 30-Dec-1996 ```
```PreviousCouponDate = cpndatep('14 Mar 1997', '30 Jun 2000',... 2, 0, 1); datestr(PreviousCouponDate) ```
```ans = 31-Dec-1996 ```
```Maturity = ['30 Apr 2000'; '31 May 2000'; '30 Jun 2000']; PreviousCouponDate = cpndatep('14 Mar 1997', Maturity); datestr(PreviousCouponDate) ```
```ans = 31-Oct-1996 30-Nov-1996 31-Dec-1996 ```